Botox can lead to significant weight loss for the management of obesity

Intraparietal gastric botulinum toxin-A injection (Botox) can lead to significant weight loss and may contribute to the development of effective, minimally-invasive approaches for the management of obesity, according to researchers from Turkey. However, they noted that further studies with larger sample sizes and longer follow-up periods are needed to confirm these findings.

This study investigated the effects of intragastric botulinum toxin-A injection on weight loss and to evaluate the ratio of weight loss achieved. The researchers recruited 500 patients who had undergone gastric botulinum toxin-A application and completed at least six months of regular follow-up.

The primary outcome parameters were changes in body weight, BMI and subjective appetite levels. For subgroup analysis, patients were divided into four groups based on baseline BMI: Group 1: <30kg/m², Group 2: 30–34.9kg/m², Group 3: 35–39.9kg/m² and Group 4: ≥40kg/m². Patients were injected intramuscularly with 1000 U of botulinum toxin-A in the antrum and fundus regions of the stomach via endoscopy under sedation anaesthesia (midazolam and propofol). Patients were monitored for two hours after the procedure and were then discharged. A low-calorie diet and active life support were provided under the guidance of a dietician for six months after the procedure.

The procedure

The endoscopic procedure was performed on all patients using the same technique. Under sedation anaesthesia, patients underwent endoscopy in the endoscopy unit. Sedation was achieved using intravenous midazolam (2.5–5 mg) and propofol (50–100 mg) administered under anaesthesiologist supervision. A total of 1000 U of BTX-A (Dysport, Ipsen Biopharm) was diluted with 8 mL of 0.9% NaCl saline. The antrum region was injected intramuscularly with 750 U to 30 spots, and the fundus region was injected intramuscularly with 250 U to 10 spots, with 1 mL at each spot using a sclerotherapy needle (Interject, Boston Scientific). Starting from the pyloric region, patients were injected at 40 regions in the stomach. The same injection map was used in all patients. Patients were monitored for two hours after the procedure and were then discharged.

The low-calorie diet was personalised according to basal metabolic rate (calculated using the Harris–Benedict formula) with a target of 500–1000 kcal/day deficit. Macronutrient distribution was balanced (45% carbohydrate, 30% fat, 25% protein). Adherence to the standardised post-procedure low-calorie diet and physical activity recommendations was monitored through monthly in-person follow-up visits and direct interviews with the dietician. Patients were asked to self-report their daily food intake and physical activity patterns, and these reports were reviewed during each visit. In the 6th month, patients were evaluated in terms of appetite and feelings of satiety after meals.

Failure to lose weight was defined as losing less than 10% of baseline body weight at the end of the 6-month follow-up period, despite undergoing the standardized post-procedure diet and activity programme.

Outcomes

Of the 500 patients, 413 were female (82.6%) and 87 male (17.4%), with a mean age of 37.93±10.11 years and a mean BMI of 34.59±6.09 kg/m2. The initial weight and height of patients were 95.99 ± 19.29 kg and 166.23 ± 7.88 cm, respectively. At the end of the third and sixth months, all subjects lost body weight, with mean weight loss ratios of 13.9±4.4%, 15.1±4.9%, 16%±3.6% and 16.4±4.2 at the third month and 19.2±6.6%, 20.5±7.0%, 22.4±5.2% and 23.2±6.3% at the sixth month for Groups 1, 2, 3 and 4, respectively (Table 1).

Table 1: Weight Loss and BMI Reduction Data in Subgroups at the 3rd and 6th months After Intragastric Injection of Botulinum Toxin Type-A

At the end of the sixth month, 319 (63.8%) of patients exercised regularly, while 281 (36.2%) did not. The proportion of patients who exercised regularly and lost weight in six months was significantly higher than those who did not exercise regularly (p=0.05). Among patients who underwent a diet programme, 433 (86.6%) did so regularly, while 67 did not. The mean weight and BMI reduction for six months post-Btx treatment in patients undergoing regular diet were significantly higher than those who did not undergo a regular diet programme (p=0.001 and p=0.02, respectively).

The mean BMI and weight were significantly different from the baseline values at the end of the third and sixth months for Groups 1, 2, 3 and 4. Mean body weight loss percentages were significantly higher in Groups 3 and 4 when compared to Groups 1 and 2 at the second, third and sixth-month time points. There was a decreasing trend in body weight until the end of the third and sixth months for all subjects. Nearly all subjects reported feeling early satiety in follow-up visits.

At the end of the six-month follow-up, the weight of patients decreased by a mean of 20.6kg after Btx application (p=0.001). When this comparison was made in terms of BMI, a mean decrease of 7.49 kg/m2 was detected in patients after six months (p=0.001). Of the patients, 447 (94.8%) stated that their appetite decreased, and they felt satiated for six months, while the remaining 53 (5.2%) patients stated that there was no change in their appetite and duration of satiety.

Out of the 500 patients who received gastric Btx-A treatment, 38 patients (7.6%) lost less than 10% of their body weight, which was considered an unsuccessful treatment. Conversely, 462 patients (92.4%) lost more than 10% of their body weight, which was considered a successful treatment (p=0.001). No acute side effects were observed immediately following the endoscopic procedure. However, eight patients reported experiencing nausea and vomiting, 23 patients experienced abdominal cramps and 55 patients experienced constipation during the follow-up period. No serious adverse events or procedure-related mortality occurred.

The researchers acknowledge that their study has some limitations, including the absence of a placebo group, the relatively short follow-up period of six months, and the inability to monitor ghrelin levels in patients who received gastric Btx-A injection.

“However, our results suggest that gastric Btx-A injection is significantly effective for obese patients and may be a promising option for those who cannot undergo surgery. Therefore, further prospective, placebo-controlled studies with longer follow-up periods should be conducted to assess the long-term effectiveness and safety of gastric Btx-A injection therapy.

“In conclusion, our study supports the effectiveness and safety of intraparietal gastric Botox injection for weight loss in obese patients,” the authors stated. “Further studies are needed to establish optimal dosing strategies and to identify the patient population that would benefit the most from this treatment.”

The findings were reported in the paper, ‘Effects of Intraparietal Gastric Botulinum Toxin-A Injection on Weight Loss: A Retrospective Study of 500 Patients’, published in Dovepress. To access this paper, please click here